Easy opening container construction



Dec. 16, 1958 H. G. ZASTROW EASY OPENING CONTAINER CONSTRUCTION Filed Oct. 18. 1954 INVENTOR Hare/d G ZasfroW BY g} ATTORNEY United States Patent ,1;

EASY OPENING CONTAINER CONSTRUCTION Harold G. Zastrow, Minneapolis, Minn., assignor to Waldorf Paper Products Company, Ramsey County, Minn., a corporation of Minnesota Application October 18, 1954, Serial No. 462,804

1 Claim. .(Cl. 229-51) This invention relates to an improvement in con tainers and deals particularly with a type of container which may be easily opened.

Recently it has been proposed to provide tear strips in corrugated containers, these tear strips usually encircling the four walls of the container or extending about at least three of the walls so that the container may be vertically separated into upper and lower portions. However, in some instances it is desirable to divide the container vertically into two vertical sections. It is With this type of container that the present invention is involved.

It is the object of the present invention to.provide a container having four hingedly connected walls which are connected in tubular form. These walls are provided with upper and lower closing flaps which-form top and bottom container closures. Each closure is formed in the usual manner by folding two of the flaps down into a common plane, these flaps usually meeting at the center of the container. The remaining two opposed flaps are then folded down to overlie the first folded flaps and are secured thereto. These last folded flaps may meet at the center of the container or may terminate in spaced relation. Tear strips are provided in the last mentioned flaps and through the walls to which they are connected so that the container may be divided into two vertical parts. A feature of the present invention lies in the fact that after the tear strips have been removed the container is divided into two parts which may serve as trays to support the carton contents. Furthermore, the tear strips aresso arranged as to eliminate any chance of impairing the strength of the walls in which they are located, although it has been found by tests that little if any weakness will result in any case.

These and other objects and novel features of my invention will be more clearly and fully set forth in the following specification and claim.

In the drawings forming a part of the specification:

Figure l is a diagrammatic view of the container blank from which the container is formed.

Figure 2 is a perspective view of the sealed container.

Figure 3 is a view similar to Figure 2 showing the container partially open.

Figure 4 is a sectional view through portions of the container showing the tear strip therein.

The container is of usual form including four wall panels 10, 11, 12 and 13. The panels and 11 are connected by a fold line 14. The panels 11 and 12 are connected by a fold line 15. The panels 12 and 13 are connected by a fold line 16. The free edges of the panels 10 and 11 are taped or otherwise secured together to forma generally rectangular tube.

The panels described are connected along parallel fold lines 17 and 19 to top and bottom closing flaps. Top closing flaps 20, 21, 22 and 23 are connected along the fold line 17 to the panels 10, 11, 12 and 13, respectively. In a similar manner, bottom closing flaps n dfiec. 16, 5

2 a 24, 25, 26 and 27 are connected by the fold line 19 to the lower edges of the panels 10, 11, 12 and 13,' respectively.

When the container is taped or secured alongthe manufacturers joint, it may be closed by folding the bottom flaps 25 and 27 into a common plane and folding the remaining opposed flaps 24 and 26 over these flaps 25 and 27 and adhering them in place.

Similarly the top of the container may be closed by folding the flaps 21 and 23 into a common plane and then folding the flaps 20 and 22 thereover and adhering them in place.

In view of the fact that tear strips actually function more effectively when the outlines intersect the corrugations, the container usually is formed with the corrugations extending horizontally rather than vertically as is more usual practice.

The tear strips are formed by weakening two spaced parallel lines in the inner liner of the corrugated board. In Figure 4 it Will be noted that the corrugated board includes an inner lining sheet 29, an outer liner 30 and intermediate corrugated medium 31 which is adhered in corrugated form by the liners 29 and 30. In forming the tear strips, the inner liner usually is provided with parallel-slits 32 and 33 which are parallel and in closely spaced relation. When an end of the area between these lines of weakness is grasped and pulled outwardly the strip 34 between the weakened lines tears through the corrugated layer 31 and the outer layer 30 to produce a tear strip. In other words the portion of the board comprising the strip 34 and the portions of the liner 30 and the corrugated medium 31 lying outwardly of the strip 34 is torn through the sheet and is removed.

One such tear strip 34 is formed in the panel 10 to extend through the connected flaps 20 and 24. A similar strip 35 is defined by similar lines of weakness extending through the panel 12 and the connected flaps 22 and 26.

Inorder to simplify the opening operation, notches 36 are provided adjoining one end of the tear strip 34 in the edge of the flap 20 and similar notches 37 are provided at the end of the tear strip 35 in the flap 22. By grasping the portion of the board between, the notches 37 and exerting an outward pull one tear strip is removed as is indicated in Figure 3 of the drawings. By'engaging the board between the notches 37 and exerting an outward pull, the other tear strip 35 may be removed.

As the top flaps 21 and 23 and the bottom flaps 25 and 27 meet and abut, the removal of the tear strips leaves the container divided into two vertical sections which may be separated for removal of the contents. The

two halves of'the box may also be used as trays.

In accordance with the patent statutes, I have described the principles of construction and operation of my containers, and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that obvious changes may be made within the scope of the following claim without departing from the spirit of my invention.

I claim:

A carton having four side walls connected together in tubular relation; each end of said carton having a first pair of flaps extending from one parallel pair of side walls and a second pair of flaps extending from the other parallel pair of said four side walls; each pair offlaps extending from the first mentioned parallel pair of side walls being substantially in edge abutting relation, and each pair of flaps extending from the second mentioned pair of parallel side walls being in edge spacedrelation and in superimposed relation to the corresponding flaps of "the first mentioned pairo'f parallel side walls, a tear strip extending longitudinally and medially of each of said second mentioned parallel side walls and across the flaps thereof substantially to the free edges thereof, the

ends ofsaidtearstripsbeingaligned with, and overlying,

the's'a'id'zibutting edges of said first mentioned opposed flaps.

References Cited in the file of this patent UNITED STATES PATENTS 

